How to Make Prefabricated Panels for House Roofs

There are mainly two ways to make prefabricated panels for house roofs: foam-core structure and specially-made prefabricated panel assembly. Here are the specific production steps:

Production of Prefabricated Panels with Foam-Core Structure

1. Mold Making: Workers use steel plates to form a large mold, securing its shape by tightening screws. Then, a mold release agent is sprayed on the inner walls of the mold. This step aims to prevent the subsequent poured concrete from adhering to the mold, ensuring the surface integrity of the prefabricated panel during demolding.
2. Distribution Reinforcement Placement: The first layer of steel reinforcement framework (distribution reinforcement) is precisely placed at the bottom of the mold, with its dimensions matching the mold precisely. The function of the distribution reinforcement is to enhance the overall integrity of the concrete structure and disperse the load.
3. Concrete Layer Pouring: A layer of concrete about four centimeters thick is poured over the distribution reinforcement, forming the bottom structure of the prefabricated panel.
4. Foam Board Placement: Giant foam boards with a thickness of 15 centimeters are placed on the concrete layer. The foam boards are connected and fixed with iron hooks to ensure the stability of the foam layer. The foam boards serve as thermal insulation.
5. Load-Bearing Reinforcement Placement: A second layer of steel reinforcement framework is laid on the foam boards, and several strands of steel strands with extremely high tensile strength (load-bearing reinforcement) are threaded through. The load-bearing reinforcement is the main load-bearing component of the prefabricated panel, responsible for bearing the load on the roof.
6. Pretensioning Treatment: Special equipment is used to stretch each steel strand to its ultimate strength, putting the steel reinforcement in a prestressed state. Then, a second layer of concrete is poured. Prestressing technology can improve the crack resistance and load-bearing capacity of the prefabricated panel.
7. Concrete Curing: After the concrete has initially set, a vibrating rod is used to vibrate and remove air bubbles to prevent cracking. Then, the prefabricated panel is sent to a basement for four hours of steam curing to accelerate concrete hardening and enhance strength.
8. Completion of the Prefabricated Panel: After curing, the pretensioned steel strands are released. The prefabricated panel is lifted by its four corners using a gantry crane, and the excess steel bars at both ends are cut off with an angle grinder, completing the production of one prefabricated panel.

Assembly Method of Specially-Made Prefabricated Panels

A circular skylight tray is propped up in the middle of the roof, and the tray is fixed with crossbeams. A thick wooden board is placed on top. This method does not rely on steel reinforcement and cement but requires ensuring structural stability and is suitable for lightweight roofs or temporary buildings.